Improvement in scroll-sawing machines



vL. c. PRATT.

scRoLL-SAWING MACHINE. y No.169,475. Pumped Nov.v2,1s75.

\ l i l l ATTORNEYS.

MPETERS. PHoTmLITMUGRAPHER. WASHINGTUN. mp.

4UNITED STATES PATENT OFFICEc LEMUEL U. PRATT, OF NEW YORK, N. Y.

IMPROVEMENT IN SCROLL-SAWING MACHINES.

Specification forming part'of Iletters Patent No. 169,475. dated November 2, 1875 application filed August 21, 1875.

To all 'whom t may concern Be it known that I, LEMUEL C. PRATT, of the city, county, and State of New York, have invented an Improvement in Scroll-Sawing Machines, of which the following is a specification:

The object of my invention is to effect, by simple and cheap contrivance, sufficient forward and back motion of a straight saw working on a pivot to run it in one and the same line at the cutting-point, so as to cut more evenly than such saws now do.

The invention is specially designed for simple and cheap saws for Vboys and amateurs.

The invention will rst be described in connection with drawing, and then pointed out in the claim.

Figure lis a longitudinal sectional elevation of a machine contrived according to-my invention. Fig. 2 is a longitudinal section, showing a modication of the pivot and cam; and Fig. 3 is a horizontal section.

Similar letters of reference indicate corresponding parts.

A is the table of the machine; B, the arms carrying the saw G, and working on a pivot, D, the arms being connected together to form a simple and cheap frame or gate to the saw.

E is the spring for raising the saw, which will be forced down by a foot treadle or other` means. F represents the cam, which is to cause the forward and backward motion alone, or in conjunction with the spring E. In Fig. 1 this cam is a stationary curved piece, against which the part G of the saw-frame rocks, While the pivot D slides forward and backward, the frame being held up against the cam by the spring. n The pivot D may, in this case, be above or below the table, or both. In Fig. 2 the cam is a curved slot, working on a pin, H, and the pivot-pin D is in a slotted hole, I, in the saw-frame. In this case the cam effects the yforward and backward motions entirely without the aid of the spring; butin Fig. l the spring is necessary to keep to the cam.

Having thus described myinvention, I claimv as new and desire to secure by Letters Patent- The combination, with table A and cam F, of the bifurcated saw-carrier B B, working on pivot D, as and for the purpose specified.

` LEMUEL G. PRATT. Witnesses:

A. P. THAYER, ALEX. F. ROBERTS.

the frame up 

